Dual Offer + FREE Dr Advice | WhatsApp Prescription | Book Home Visit ✆ 09220145540

Menu Icon
  • Home
  • Health Tips
  • Congenital Heart Defects Types Causes Diagnosis Treatment

Congenital Heart Defects Types Causes Diagnosis Treatment

Congenital Heart Defects Types Causes Diagnosis Treatment

Posted By HealthcareOnTime Team Posted on 2022-01-26

Congenital Heart Defects are structural and functional anomalies of the heart and cardiocirculatory system, present at birth due to abnormal heart development. Heart, the first functional organ formed in a human embryo as a single tubular structure at around 1819 days post fertilisation, starts beating and pumping blood by the 5 week of pregnancy. A septum is a wall that grows and separates heart chambers: upper (atrial) and lower (ventricular) into left and right sides, preventing mixing of blood. Normal heartbeat can be easily recognised in the week 6 of pregnancy from gestation and is also one of the most crucial periods for subsequent embryonic and prenatal development, requiring utmost care. If something goes wrong during formation of the endocardial tubes or cardiac looping after the heart tube has stretched by day 23 or during differentiation of heart tube into the atrial and ventricular junctions and chambers, it often results into structural or functional anomalies in the fetus's heart.

Congenital Heart Defects Types Causes Diagnosis Treatment

Types of Congenital Heart Defects
The profile of Congenital Heart Defects vary depending upon the age group, ranging from simple defects to complex ones which generally arise due to combination of many simple complications; improper location of the blood vessels which move to and from the heart, erroneous developmental process of heart, etc. These defects range from simple "holes" between heart chambers to severe malformations like complete absence of one or more of the heart's chambers or valves and hence can be broadly classified as:

I. Acyanotic Congenital Heart Defects or Left-to-right shunts These include deviations from the normal cardiac shunt wherein there is a balance between the systemie and pulmonary circulations. The left-to-right shunts cause back-leak of blood from the systemic to the pulmonary circulation leading to an increase in blood pressure as well as volume in the latter. These septal defects being very common in newborns, don't normally interfere with the amount of oxygen or Blood that reaches the body tissues. These Congenital Heart Defects are asymptomatic or show mild to severe symptoms which can either have an acute or delayed onset, and can be further sub-divided into:

Ventricular septal defect (VSD) VSD results due to presence of a defect or hole in the membranous part of the interventricular septum which forces blood from the left side of the heart to the right side at every heartbeat. Oxygen-rich blood reverts to the lungs, thereby hampering the entry of the not yet oxygen-rich blood to the lungs. Since huge volume of blood enters the lungs, the heart pumps extra blood making VSD affected newborns easily fatigued.

Atrial septal defect (ASD) One of the least complex forms of Congenital Heart Defects, ASD is characterised by a hole or defect between the atria leading to leakage of oxygen-rich blood to the right side of the heart which pushes it back to the lungs increasing the blood flow significantly. ASDs primarily include secundum defect (hole in the middle of atrial septum), primum defect (associated with a cleft in the mitral valve causing blood leakage) and sinus venosus defect (leads to abnormal drainage from the right upper pulmonary vein).

Atrioventricular canal defect (AVCD) One of the most complex Congenital Heart Defects, AVCD can be best elucidated as a large hole in the middle of the baby's heart. Lack of differentiation of atria and ventricles into separate chambers, and of the mitral and tricuspid valves into two separate valves leads to formation of a large connection between the two atria, two ventricles and an AV valve where separate mitral and tricuspid valves should exist. AVCDs become more complicated when there is an improper formation of one of the ventricles, an obstruction to aorta or straddling valves; which increases the blood flow to lungs through septal defects damaging the heart's blood vessels. Regurgitation of valve occurs upon blood leakage from ventricular chambers to atrial chambers due to its improper closure, leading to heart enlargement.

Patent ductus arteriosus (PDA) PDA occurs when there is failure of normal physiologic closure of ductus arteriosus post baby's birth and there is a persistent connection between the aorta and pulmonary artery, leading to excessive blood flow to the lungs damaging heart's blood vessels. PDA can be asymptomatic or in severe cases, may result in congestive heart failure with increasing age.

II. Right/Left heart obstructive defects Obstructive defects result due to abnormal blockage or narrowing of heart valves, arteries or veins, thereby leading to heart enlargement and hypertension; its common sub-types are:
Pulmonic stenosis Occurs with a combination of other Congenital Heart Defects and is a fixed or dynamic anatomic impediment of blood flow from heart's right ventricle to the pulmonary artery causing mild to moderately severe desaturation or cyanosis.
Aortic stenosis There is narrowing of the aortic valve (aorta is the main artery that carries blood out of the heart to the rest of the body) opening that leads to aortic stenosis, making the left ventricle to pump blood harder. Thus, the blood doesn't flow freely to the aorta causing high blood pressure subsequently decreasing blood flow from the heart.
Coarctation of the aorta A very common CHD, and is characterised by narrowing of a discrete or long segment of aorta and if undiagnosed leads to congestive heart failure in infants. This condition causes significant afterload on the left ventricle resulting in increased wall pressure and ventricular hypertrophy.
III. Cyanotic Congenital Heart Defects/Right-to-left shunt In these, deoxygenated blood bypass the pulmonary circulation (lungs) and enters the systemie circulation, causing mixing of oxygenated and deoxygenated blood leading to right-to-left shunting and pulmonary venous desaturation. This collateral circulation increases pulmonary vascular resistance resulting in cyanosis.

Tetralogy of Fallot (TOF) TOF is a combination of four heart defects namely, VSD, pulmonic stenosis, right ventricular hypertrophy and overriding of aorta, which together obstruct pulmonary blood flow leading to pumping of a mixture of oxygenated and deoxygenated blood throughout the body. A child with unrepaired TOF may often feel dizzy and fatigued along with an impending risk of arrhythmia and endocarditis.

Transposition of the great arteries (TGA) A serious yet rare condition arising due to reversal of the two main arteries which exit the heart; in short they are transposed. This leads to parallel circulation and complete admixture of the pulmonary and systemic venous returns, eventually pumping low-oxygenated blood to the body through aorta. Infants don't survive unless there are inter circulatory shunts through septal defects.

Tricuspid atresia This condition is characterised by an absence of the tricuspid valve (between the right atrium and ventricle) causing left ventricular hypertrophy due to absence of proper connection between the right atrium and right ventricle. Progressive cyanosis occurs in the newborn since the first day of life. In such cases, presence of other anatomical variations like ASD or VSD contributes to symptom development as well as treatment efficacy.

Eisenmenger complex This condition highlights a stage in the CHD, when pulmonary Hypertension becomes irreversible and the defect becomes inoperable. An initial high blood pressure on left ventricle creates left-to- right shunt, causing pulmonary hypertension by increasing the blood flow to lungs through pulmonary artery. Injured lung arterioles increase blood flow resistance gradually until the shunting direction is reversed to right-to-left through VSD, causing cyanosis.

Causes of Congenital Heart Defects
Multiple factors are responsible for altering the developmental process of heart during the initial stages of fetus development but in most the specific cause of a CHD is unknown.

Genetic factors: 50% of newborns with trisomy 21 and nearly all trisomy 18 affected, acquire atrial or ventricular septal defects or AV canal lesions whereas the risk of Congenital Heart Defects increases to 80% in trisomy 13 affected newborns. One third of females with Turner syndrome exhibit left/ right heart obstructive defects whereas 50% of 47 XXY males (Klinefelter syndome) show PDA and other septal defects. Single gene mutations in GATA4, NKX2.5, Myosin heavy chain 6 gene (MYH6), etc. and copy number variations have been linked to isolated Congenital Heart Defects like atrial septal defects.

Lifestyle factors: Uncontrolled and poor management of maternal infectious diseases like rubella or Syphilis, conditions like Diabetes, maternal iodine and folic acid deficiencies; alcohol and drugs intake increase the risk of Congenital Heart Defects.

Environmental exposures: During the 1" trimester, exposure to anticonvulsant or dermatological medications, industrial chemicals, radiation or lithium salts for manic-depressive illness may cause structural abnormalities in fetus's heart.

Signs and Symptoms of Congenital Heart Defects
During pregnancy exchange of oxygen and carbon dioxide takes place via the placenta and not through the fetus's lungs, thus preventing development of any breathing complications due to severe underlying heart defects until circulation transitions in the newborn state post- birth. Early signs and symptoms of Congenital Heart Defects depend on severity of its type which often go undetected until later in life while other Congenital Heart Defects initially manifest by the presence of:
- Heart murmur
- Lung congestion
- Shortness of breath and dehydration
- Rapid breathing in case of TOF and TGA
- Fatigue and fussiness
- Cyanosis
- Respiratory tract infections
- Under development of limbs and muscles
- Poor weight gain, feeding, growth and development
- Cardiac failure in severe Congenital Heart Defects

Diagnosis of Congenital Heart Defects Congenital Heart Defects are often suspected in newborns post-birth or in a few weeks, if cyanosis or heart murmurs are present. A pediatric cardiologist conducts physical examination for confirming symptoms upon listening to the child's heart and lungs with a stethoscope.

Imaging Tests for Congenital Heart Defects
Fetal Echocardiography This test is recommended to confirm cases of suspected CHD. This echo test acquires a complete motion picture of the baby's heart using sound waves between 18-22 weeks of pregnancy, to identify abnormalities in the heart muscle and valves.

Electrocardiogram (ECG or EKG) ECG test can diagnose enlargement of heart chambers by recording the heart's electrical activity, its beating and rhythm (steady or irregular)

Chest X-Ray This provides accurate pictures of heart and lungs aiding in diagnosing extra fluid accumulation or extra blood flow in lungs along with probing for heart chamber enlargement.

Pulse Oximetry A small sensor attached to the finger or toe can provide an estimate of oxygen concentration in blood, where too little levels aid in detecting severe heart problems.

Cardiac Catheterisation A flexible thin tube - catheter is inserted into the baby's vein in arm, groin or neck, then threaded to the heart followed with an injection of a special dye through the catheter, into the blood vessel or heart chambers which enables the cardiologist to measure the pressure and oxygen levels inside to identify cases of blood mixing.

Treatment and Management of Congenital Heart Defects
Sometimes, mild Congenital Heart Defects like small holes may correct themselves with increasing age, but the severe ones need immediate treatment upon diagnosis. Depending on the type, a cardiac surgeon uses catheterisation to repair septal defects or narrowed valves without surgically opening the chest and heart. If catheterisation fails, open heart surgeries are performed which involve opening the chest and stopping the heart temporarily for repair. If a serious defect is irreparable, heart transplants are performed. If Congenital Heart Defects are diagnosed in childhood or adulthood, along with the combination of other treatments, certain medications like angiotensin-converting enzyme inhibitors, beta blockers, diuretics, etc. are also prescribed to ease stress on heart by lowering blood pressure and fluid accumulation in chest.

An early diagnosis though mitigates future complications and increases life expectancy of the affected, a speedy recovery only entails upon effective manage ment of the patient. Severe CHD affected kids require multiple corrective surgeries throughout life with ongoing care and support from families along with scheduled follow-up with their cardiologist. Certain restrictions must be exercised like limiting strenuous physical activities. In case of prosthetic devices implantation like heart valves, antibiotics must be taken to prevent infections. Congenital Heart Defects can't be prevented but following few precautionary measures can reduce their risk, if exercised by women before/during Pregnancy.
Get vaccinated against Rubella infection before you try to conceive.
Intake of multivitamin tablets with folic acid is a must to reduce birth defects.
Abstain from alcohol or drugs and other chemical exposure activities like painting, etc.
Control and manage chronic conditions like diabetes, epilepsy, etc

After facing two surgeries and pulmonary valve replacement, Asha now a software engineer and a mother of a healthy daughter, belongs to one of the first few TOF survivors. Individuals with CHD need lifetime monitoring since their healthcare needs are still under research with an unknown prognosis and life expectancy.

Contrary to their sizes, it's frightening to even imagine a little innocent one suffering from something grave. It is time the big hearts in us reach out to help them cope with something, which scarred their life even before their birth .


View Our Editorial Policy
Was this article helpful?

Trending Health & Fitness Web Stories

Find Latest Health Web Stories, Fitness Photo Stories, Health AMP Stories.VIEW ALL

Did you catch our latest post? JOIN US

Facebook LinkedIn Instagram Twitter YouTube

Contact Us

Email: info@healthcareontime.com | Phone No: 09220145540 | Whatsapp: 9820693367
  • Copyright 2024 HealthCareOnTime.com, All Rights Reserved
  • Disclaimer: HealthcareOnTime offers extensively researched information, including laboratory testing for health screening. However, we must emphasize that this content is not intended as a substitute for professional medical advice or diagnosis. Always prioritize consulting your healthcare provider for accurate medical guidance and personalized treatment. Remember, your health is of paramount importance, and only a qualified medical professional can make precise determinations regarding your well-being.
DMCA.com Protection Status HealthCareOnTime.com Protection Status HealthCareOnTime.com Protection Status